Pressure sensitive sensor, object detecting device and opening, attachment structure thereof and opening-and-closing device

ABSTRACT

A pressure sensitive sensor provided in at least one of an opening section and an opening and closing section for opening and closing the opening section and serving to detect pinching of an object between the opening section and the opening and closing section based on an output signal generated by deformation upon receipt of external force, including a pressure sensitive element  33  for generating an output signal corresponding to deformation and a support element  35  for supporting the pressure sensitive element  33  on at least one of the opening section and the opening and closing section, the support element  35  including at least a first deformation section  37  having a first elastic modulus and serving to increase deformation of the pressure sensitive sensor  17 , and a second deformation section  39  having a second elastic modulus which is higher than the first elastic modulus.

BACKGROUND OF THE INVENTION

The present invention relates to a pressure sensitive sensor, anobject-detecting device, attachment structure thereof and an opening andclosing device. More particularly, the invention relates to a techniquefor improvement to reliably operate a sensor and a pressure sensitivesensor attachment structure and an opening and closing device which aresuitably used for a power window device of a car which requires anobject pinching preventing function.

Conventionally, there have been disclosed many examples in which apressure sensitive sensor of such a type as to close a contact point bypressing or a piezoelectric sensor utilizing a piezoelectric element isused for a pressure sensitive sensor to be used for preventing an objectfrom being pinched. When the piezoelectric sensor is deformed by thepressing of an object, a voltage pulse is output from the piezoelectricsensor and the presence of pinching of the object is detected based onthe presence of the voltage pulse. In the case in which these pressuresensitive sensors are applied to prevent pinching in the power windowdevice of a car, a pressure sensitive switch or a piezoelectric sensoris provided along the window frame of a door and is deformed by anobject when the object is pinched between the window frame and awindowpane, for example. If the pressure sensitive switch is closed or apredetermined voltage pulse is output from the piezoelectric sensor whenthe windowpane is to be closed, it is assumed that the object is pinchedand the direction of rotation of an electric motor is reversed toeliminate the pinching.

There has been proposed the pinching detecting device for the powerwindow device of this type comprising a pressure sensitive sensor 210having conductive contact wires 202, 203, 204 and 205 opposed on theinner circumference of a long string-shaped elastic cylinder 201 whichis buried in elastic support means provided along the edge of a windowframe as shown in FIGS. 22A and 22B (for example, see Japanese PatentDocument JP-A-2001-153734).

The pressure sensitive sensor 210 serves to output a predetermineddetection signal when conductive contact wires to be opposed to eachother in the elastic cylinder 201 come in contact with each other asshown in FIG. 23B when the elastic cylinder 201 is crushed in a constantamount or more by pinching an object.

In the pinching detecting device using the pressure sensitive sensor210, however, when the pressure sensitive sensor 210 is bent as shown inFIG. 23A corresponding to the corner section of a window frame in orderto be provided along the corner section of the window frame in the frontseat of a vehicle, for example, there is a possibility that the elasticcylinder 201 might be crushed in a bending position and the contactwires might thereby come in contact with each other, resulting inerroneous detection as shown in FIG. 23B. For this reason, the pressuresensitive sensor 210 has conventionally been provided independently foreach of almost rectilinear sides constituting the window frame such thatone pressure sensitive sensor 210 is not provided across the cornersection of the window frame.

In such a pressure sensitive sensor attachment structure, however, thereis a problem in that the number of the pressure sensitive sensors 210 tobe used is increased and a great deal of time and labor is required fora processing of connecting a lead wire from each pressure sensitivesensor 210.

In the pressure sensitive sensor attachment structure, moreover, apressure sensitive sensor is not present in the corner section itself ofa window frame. For this reason, there is a possibility that the localpinching of an object in the corner section of the window frame mightnot be detected.

In the pressure sensitive sensor 210, furthermore, even if the sectionof the pressure sensitive sensor 210 is crushed due to the pinching ofan object, the contact of the contact wires is not generated until thesection is crushed in a constant amount or more. Consequently, thepinching is detected with a delay. As a result, there is a problem inthat an operation for closing a windowpane is stopped with a delay.

In the case in which an inclined side is provided on the window frame asin an opening and closing door in the front seat of a vehicle, forceacting in such a direction as to deform the section of the pressuresensitive sensor 210 is changed into a component of force which issmaller than force for lifting a windowpane pinching an object when theobject is pinched in the pressure sensitive sensor 210 provided on theinclined side. As a result, the elastic cylinder 201 is not sufficientlydeformed elastically. Finally, there is a possibility that the pinchingof the object might not be detected quickly.

On the other hand, in the piezoelectric sensor, moreover, there is aproblem in that the piezoelectric sensor is fixed to the window frameand is thus deformed with difficulty even if the object presses thepiezoelectric sensor, and a voltage pulse having a sufficient magnitudefor detection is not generated from the piezoelectric sensor whenpinching is to be detected. For this reason, the voltage pulse having asufficient magnitude is not output from the piezoelectric sensor.Therefore, a windowpane continuously carries out a closing operationuntil the voltage pulse has a detection threshold or more for thepinching. Consequently, there is a possibility that a load applied tothe object might be increased to damage the object before the pinchingis eliminated.

Therefore, there has been disclosed in Japanese Patent DocumentJP-A-2001-324393 a technique in which a pressure sensitive sensorutilizing a novel piezoelectric element formed like a flexible wire andserving to generate an output signal corresponding to the accelerationcomponent of deformation is used to enhance a detection sensitivity,thereby producing great pinching prevention effects (see FIGS. 1, 2 and4).

The pressure sensitive sensor for generating an output signalcorresponding to an acceleration component is attached to a window frame1 with a structure shown in FIG. 14. More specifically, a pressuresensitive sensor 4 comprises a flexible piezoelectric sensor 2 andsupport means 3, and the support means 3 has the piezoelectric sensor 2provided in the vicinity of a lowermost portion and is formed of anelastic member such as rubber having a flexibility or a foamed resinmember. Moreover, the thickness of the support means 3 provided aroundthe piezoelectric sensor 2 is reduced such that the piezoelectric sensor2 can easily be deformed. The support means 3 has a deformationincreasing section including a hollow section 4 and a side wall section5 which serves to increase the deformation of the piezoelectric sensor2.

In the attachment structure, the deformation of the piezoelectric sensor2 is mainly increased by the deformation of the deformation increasingsection so that a high detection sensitivity can be realized. As aresult of the vigorous investigations of the inventors, however, itcould be known that a detection capability can be enhanced still more ata low cost by varying the signal processing of the piezoelectric sensor2 or changing the shape of the support means 3.

SUMMARY OF THE INVENTION

It is a first object of the invention to provide a pressure sensitivesensor, an object detecting device and an opening and closing devicewhich use a piezoelectric sensor for detecting an acceleration componentto stably detect an object with high precision in any situation and areinexpensive.

Second object is to provide a pressure sensitive sensor attachmentstructure and an opening and closing device which can detect thegeneration of pinching reliably and rapidly also in an inclined sectionand a corner section in a window frame, and furthermore, can use onlyone pressure sensitive sensor to be provided and can easily carry outthe processing of a lead wire led from the pressure sensitive sensor.

The first object can be achieved by the following structure.

(1) A pressure sensitive sensor provided in at least one of an openingsection and an opening and closing section for opening and closing theopening section and serving to detect pinching of an object between theopening section and the opening and closing section based on an outputsignal generated by deformation upon receipt of external force,comprising pressure sensitive means for generating an output signalcorresponding to deformation and support means for supporting thepressure sensitive means on at least one of the opening section and theopening and closing section, the support means including at least afirst deformation section having a first elastic modulus and serving toincrease deformation of the pressure sensitive sensor, and a seconddeformation section having a second elastic modulus which is higher thanthe first elastic modulus.

(2) The pressure sensitive sensor according to (1), wherein the firstdeformation section has a hollow section and a side wall section.

(3) The pressure sensitive sensor according to (1) or (2), wherein thefirst deformation section and the second deformation section are formedseparately and are bonded to each other.

(4) The pressure sensitive sensor according to (1) or (2), wherein thesecond deformation section is formed integrally with a part of a weatherstrip of a car.

(5) The pressure sensitive sensor according to (1) or (2), wherein thesecond deformation section is a window frame of a car.

(6) The pressure sensitive sensor according to (2), wherein the firstdeformation section and the second deformation section are formedintegrally and the second deformation section has a smaller gap than thehollow section.

(7) The pressure sensitive sensor according to any of (1) to (6),wherein the pressure sensitive means is molded by using a compoundpiezoelectric member mixing chlorinated polyethylene and piezoelectricceramics powder.

(8) An object detecting device comprising the pressure sensitive sensoraccording to any of (1) to (7), and deciding means for deciding presenceof a contact of an object with the pressure sensitive sensor based on asignal output from the pressure sensitive sensor.

(9) The object detecting device according to (8), wherein the decidingmeans outputs a decision signal when the signal output from the pressuresensitive means has a preset first change amount or more.

(10) The object detecting device according to (9), wherein the decidingmeans holds the decision signal until the signal output from thepressure sensitive means which has a different polarity from thepolarity of the output signal has a preset second change amount or moreafter the signal output from the pressure sensitive means has the firstchange amount or more.

(11) An object detecting device provided in at least one of an openingsection and an opening and closing section for opening and closing theopening section and serving to detect pinching of an object between theopening section and the opening and closing section based on an outputsignal generated by deformation upon receipt of external force, anddeciding means for deciding presence of a contact of the object with thepressure sensitive sensor based on a signal output from the pressuresensitive sensor, the pressure sensitive sensor including pressuresensitive means for generating an output signal corresponding todeformation and support means for supporting the pressure sensitivemeans on at least one of the opening section and the opening and closingsection, and the deciding means outputting a decision signal when thesignal output from the pressure sensitive means has a preset firstchange amount or more, and holding the decision signal until the signaloutput from the pressure sensitive means which has a different polarityfrom the polarity of the output signal has a preset second change amountor more after the decision signal is output.

(12) An opening and closing device comprising the object detectingdevice according to any of (8) to (11), driving means for driving anopening and closing section, and control means for controlling thedriving means to stop a closing operation of the opening and closingsection or to cause the opening and closing section to carry out anopening operation when deciding means decides a contact of an objectwith a pressure sensitive sensor when the opening and closing sectioncarries out the closing operation.

The second object can be achieved by a pressure sensitive sensorattachment structure and an opening and closing device which have thefollowing structures.

(13) A pressure sensitive sensor attachment, structure provided in atleast one of an opening section having an inclined side and another sideconnected thereto through a corner section and an opening and closingmember for opening and closing the opening section and serving to detectpinching of an object between the opening section and the opening andclosing member, wherein the pressure sensitive sensor has a flexibilityand is long, and is inserted in elastic support means to be supported onthe opening section or the opening and closing member, and is providedon at least the inclined side of the opening section.

(14) A pressure sensitive sensor attachment structure provided in atleast one of an opening section having an inclined side and another sideconnected thereto through a corner section and an opening and closingmember for opening and closing the opening section and serving to detectpinching of an object between the opening section and the opening andclosing member, wherein the pressure sensitive sensor has a flexibilityand is formed like a long shaft, and is inserted in elastic supportmeans to be supported on the opening section or the opening and closingmember, and the single continuous pressure sensitive sensor is insertedin the elastic support means in a region including the inclined side andanother side.

(15) The pressure sensitive sensor attachment structure according to(13) or (14), wherein the pressure sensitive sensor serves to output anelectric signal corresponding to a deformation acceleration in elasticdeformation.

(16) The pressure sensitive sensor attachment structure according to anyof (13) to (15), wherein a piezoelectric element material of thepressure sensitive sensor is formed by a compound piezoelectric membermixing chlorinated polyethylene and piezoelectric ceramics powder.

(17) The pressure sensitive sensor attachment structure according to anyof (13) to (16), wherein a surface of the elastic support means issubjected to a high friction processing.

(18) The pressure sensitive sensor attachment structure according to anyof (13) to (16), wherein a surface of the whole elastic support means ora part thereof is a surface from which a material surface having nocoating layer is exposed.

(19) An opening and closing device comprising a pressure sensitivesensor attached with the pressure sensitive sensor attachment structureaccording to any of (13) to (18), deciding means for deciding presenceof a contact of an object with the pressure sensitive sensor based on asignal output from the pressure sensitive sensor, opening and closingmeans for operating the opening and closing member for opening andclosing the opening section, and control means for controlling theopening and closing means in order to stop the operation of the openingand closing member or to start an opening operation of the opening andclosing member when the deciding means decides that the contact with theobject is caused in response to an electric signal sent from thepressure sensitive sensor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view showing the appearance of an object detecting devicecomprising a pressure sensitive sensor and an opening and closing deviceaccording to the invention;

FIGS. 2A and 2B are views showing the structure of an A—A section inFIG. 1;

FIG. 3 is a view showing the structure of the section of a piezoelectricsensor;

FIG. 4 is a view showing the appearance of the piezoelectric sensor;

FIG. 5 is a block diagram showing the object detecting device and theopening and closing device;

FIG. 6 is an explanatory view showing the state of the pressuresensitive sensor which is obtained when an object enters and is pinchedbetween a window frame and a windowpane;

FIGS. 7A to 7C are characteristic charts showing an output signal sentfrom a filtering section, the decision output of deciding means and avoltage applied to a motor;

FIGS. 8A and 8B are another characteristic charts showing the outputsignal sent from the filtering section and the decision output of thedeciding means;

FIGS. 9A to 9C are views showing a state in which a pressure is detectedin a compression state, FIG. 9A being an explanatory view showing theapplication of a static load, FIG. 9B being an explanatory view showinga state in which a pressure is further applied, and FIG. 9C being anexplanatory view showing a state in which a pressure is detected toreturn a windowpane;

FIG. 10 is a graph representing the deformation characteristics of afirst deformation section and a second deformation section;

FIG. 11 is a sectional view showing a first variant in which a seconddeformation section is constituted separately from a weather strip;

FIG. 12 is a sectional view showing a structure according to a secondvariant in which a second deformation section and a first deformationsection are integrated;

FIG. 13 is a sectional view showing a structure according to a thirdvariant in which a second deformation section and a first deformationsection are integrated;

FIGS. 14A and 14B are views showing a state in which an object presses apressure sensitive sensor during the closing operation of a windowpane,FIG. 14A being an explanatory view showing a state obtained before thedeformation of a window frame and FIG. 14B being an explanatory viewshowing a state obtained after the deformation of the window frame;

FIG. 15 is a sectional view showing an example in which a conventionalpressure sensitive sensor for generating an output signal correspondingto an acceleration component is attached to a window frame;

FIG. 16 is an enlarged view showing the window frame of a vehicle forexplaining the pressure sensitive sensor attachment structure accordingto the invention;

FIG. 17 is an enlarged view showing a B section in FIG. 16;

FIG. 18 is a view for explaining an operation to be carried out in thecase in which an object is pinched on the inclined side of a windowframe with the pressure sensitive sensor attachment structure accordingto an embodiment of the invention;

FIG. 19 is a view for complementarily explaining deformation generatedin a piezoelectric element member in the case in which the object ispinched on the inclined side of the window frame with the pressuresensitive sensor attachment structure according to the embodiment of theinvention;

FIGS. 20A and 20B are views showing an example of the structure of adoor section on the rear seat side of a car, FIG. 20A being a viewshowing a structure in which a partition frame is provided in additionto a window frame and FIG. 20B being a view showing a structure in whichthe partition frame is not provided;

FIG. 21 is an explanatory view showing another section of a car to whichthe pressure sensitive sensor attachment structure and the opening andclosing device according to the invention are applied;

FIGS. 22A and 22B are explanatory views showing a pressure sensitivesensor to be used in a conventional pinching detecting device, FIG. 22Abeing a side view and FIG. 22B being a sectional view taken along aP1—P1 line in FIG. 22A; and

FIGS. 23A and 23B are explanatory views showing a state in which thepressure sensitive sensor to be used in the conventional pinchingdetecting device is bent, FIG. 23A being a side view and FIG. 23B beinga sectional view taken along a P2—P2 line in FIG. 23A.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment

A preferred embodiment of a pressure sensitive sensor, an objectdetecting device and an opening and closing device according to theinvention will be described below in detail with reference to thedrawings.

FIG. 1 is a view showing the appearance of an object detecting device100 comprising a pressure sensitive sensor and an opening and closingdevice 150 according to the invention, illustrating an example of thecase in which they are applied to the power window of a car. FIG. 2A isa view showing the structure of an A—A section in FIG. 1. In FIG. 2A,the right side indicates an inside of a vehicle compartment and the leftside indicates an outside of the vehicle compartment.

First of all, the basic structure of the object detecting device 100according to the embodiment is as follows. In FIG. 1, 11 denotes a doorof a car, 13 denotes a window frame to be an opening section, and 15denotes a windowpane to be an opening and closing section. 17 denotes apressure sensitive sensor which is provided on the peripheral edge ofthe end of the window frame 13. 19 denotes deciding means for deciding acontact of an object with the pressure sensitive sensor 17 based on theoutput signal of the pressure sensitive sensor 17.

Moreover, the switch gear 150 according to the embodiment is constitutedby the object detecting device 100, driving means 21 for opening andclosing the windowpane 15, and control means 23 for controlling thedriving means 21. The driving means 21 is constituted by a motor 25, awire 27, a support tool 29 for the windowpane 15, and a guide 31. Thewire 27 is moved by the motor 25, and the support tool 29 coupled to thewire 27 is vertically moved along the guide 31 so that the windowpane 15is opened and closed. The driving means 21 is not restricted to a methodusing the wire 27 described above but may employ another method.Moreover, the control means 23 may be integrated with the motor 25.

As shown in FIG. 2, the pressure sensitive sensor 17 according to theembodiment comprises a flexible piezoelectric sensor 33 to be pressuresensitive means, and support means 35. The support means 35 comprises afirst deformation section 37 having the piezoelectric sensor 33 providedin the vicinity of a lowermost portion and formed of an elastic membersuch as rubber or a foamed resin member, and a second deformationsection 39 bonded to the first deformation section 37 and fixed to thewindow frame 13. More specifically, the first deformation section 37 hasa follow section 41 and a side wall section 43, and a macro elasticmodulus obtained by integrating the hollow section 41 and the sidewallsection 43 is represented by E1 (a first elastic modulus). On the otherhand, a macro elastic modulus of the second deformation section 39 isrepresented by E2 (a second elastic modulus) which is greater than E1.In other words, in the first deformation section 37, the thickness ofthe support means 35 provided around the piezoelectric sensor 33 isreduced such that the piezoelectric sensor 33 can easily be deformed,and the deformation of the piezoelectric sensor 33 is increased.Moreover, the second deformation section 39 sets the macro elasticmodulus E2 to be greater than the elastic modulus E1 of the firstdeformation section, thereby obtaining the behavior of the deformationof the support means 35 in which the first deformation section 37 iscrushed and the second deformation section 39 is then crushed. Thesecond deformation section 39 is integrated with a weather stripprovided in the window frame 13. The support means 35 is not restrictedto a two-stage structure but a third deformation section may be furtherprovided.

Moreover, thermoplastic elastomer (TPE) can be applied to the firstdeformation section 37 and ethylene propylene rubber (EPDM) can beapplied to the second deformation section 39, for example.

Furthermore, the pressure sensitive sensor 17 is not restricted to theopening section side but may be provided on the opening and closingside.

FIG. 3 is a view showing the structure of the section of thepiezoelectric sensor 33. The piezoelectric sensor 33 has such astructure that a center electrode 45 to be an electrode for leading asignal, a ground electrode 47, a compound piezoelectric layer 49 formedby a compound piezoelectric member mixing the sintered powder ofpiezoelectric ceramic with a rubber elastic member formed of chlorinatedpolyethylene, and a covering layer 51 are laminated concentrically, aremolded like a cable and are polarized, and has a high flexibility andgenerates an output signal corresponding to deformation. The sinteredpowder of lead titanate or lead zirconate titanate is used for thepiezoelectric ceramic, for example. The piezoelectric sensor 33 ismanufactured in the following procedure. First of all, a chlorinatedpolyethylene sheet and piezoelectric ceramic having (40 to 70) vol %(lead zirconate titanate) powder are uniformly mixed like a sheet by aroll method. The sheet is cut into small pellet-shaped pieces, and thepellets are extruded continuously together with the center electrode 45,thereby forming the compound piezoelectric layer 49. Then, the groundelectrode 47 is wound around the compound piezoelectric layer 49. Thecovering layer 51 is also extruded continuously to surround the groundelectrode 47. Finally, a high DC voltage of (5 to 10) kV/mm is appliedbetween the center electrode 45 and the ground electrode 47 in order topolarize the compound piezoelectric layer 49.

When the piezoelectric ceramic powder is to be added to the chlorinatedpolyethylene, it is preferable that the piezoelectric ceramic powdershould be previously immersed in a solution of a titanium and couplingagent and should be dried. By this treatment, the surface of thepiezoelectric ceramic powder is covered with a hydrophilic group and ahydrophobic group which are contained in the titanium and couplingagent. The hydrophilic group prevents the coagulation of thepiezoelectric ceramic powder, and furthermore, the hydrophobic groupincreases a wettability of the chlorinated polyethylene and thepiezoelectric ceramic powder. As a result, the piezoelectric ceramicpowder can be uniformly added in a large amount up to 70 vol % at amaximum in the chlorinated polyethylene. It has been found that the sameeffects can be obtained by adding the titanium and coupling agent duringthe rolling of the chlorinated polyethylene and the piezoelectricceramic powder in place of the immersion in the titanium and couplingagent solution. This treatment is excellent in that the immersiontreatment in the titanium and coupling agent solution is not speciallyrequired. Thus, the chlorinated polyethylene also plays a part of abinder resin in the mixture of the piezoelectric ceramic powder.

While an ordinary metallic single conductor may be used for the centerelectrode 45, an electrode obtained by winding a metallic coil around aninsulating polymeric fiber is used. Polyester fiber which has beencommercially used in an electric blanket and a copper alloy containing 5wt % of silver are preferable for the insulating polymeric fiber and themetallic coil, respectively.

The ground electrode 47 has such a structure that a band-shapedelectrode having a metal film bonded onto a polymer layer is used and iswound around the compound piezoelectric layer 49. Since an electrodeusing polyethylene terephthalate (PET) as the polymer layer and havingan aluminum film bonded thereto has a high thermal stability at 120° C.and is also mass-produced commercially, it is preferable for the groundelectrode 47. The electrode can be connected to the deciding means 19through caulking or hold fast, for example. Moreover, a metallic singlecoil or a metallic braided wire may be wound around the aluminum film ofthe ground electrode 47 and may be thus conducted to the aluminum film,and the metallic single coil or the metallic braided wire maybe solderedto the deciding means 19. Since the soldering can be carried out, theefficiency of a work can be enhanced. In order to shield thepiezoelectric sensor from the electrical noise of an externalenvironment, it is preferable that the ground electrode 47 should bewound around the compound piezoelectric layer 49 with overlapping.

While it is preferable that vinyl chloride or polyethylene should beused for the covering layer 51, an elastic material such as rubberhaving a higher flexibility than that of the compound piezoelectriclayer 49 may be used such that the piezoelectric sensor 33 can bedeformed easily in the pressing of an object. In consideration of a heatresistance and a cold resistance of vehicle parts, a material isselected. More specifically, it is preferable that a material having asmall reduction in a flexibility at −30° C. to 85° C. should beselected. For such rubber, for example, it is preferable to useethylene-propylene rubber (EPDM), chloroprene rubber (CR), butyl rubber(IIR), silicone rubber (Si) or thermoplastic elastomer. By the structuredescribed above, the minimum curvature of the piezoelectric sensor 33can have a radius of 5 mm at a maximum.

As described above, since the compound piezoelectric member of thepiezoelectric sensor 33 has the flexibility of the chlorinatedpolyethylene and the high temperature durability of the piezoelectricceramic, a sensitivity is not reduced at a high temperature as in aconventional piezoelectric sensor using polyvinylidene fluoride as apiezoelectric and a high temperature durability is great, andfurthermore, a vulcanizing step is not required during molding likerubber such as EPDM. Consequently, it is possible to obtain an advantagethat a production efficiency is high.

FIG. 4 is a view showing the appearance of the piezoelectric sensor 33,in which a resistor 55 for disconnection detection is provided in an end53 of the piezoelectric sensor 33. The resistor 55 for disconnectiondetection is connected between the center electrode 45 and the groundelectrode 47 in the piezoelectric sensor 33. The resistor 55 fordisconnection detection also serves as a discharge section fordischarging an electric charge generated in the piezoelectric sensor 33by a pyroelectric effect so that components are rationalized. Thepiezoelectric sensor 33 is directly connected to the deciding means 19,and the piezoelectric sensor 33 and the deciding means 19 are thusintegrated. Moreover, a cable 57 for supplying a power and outputting adetection signal and a connector 59 are connected to the deciding means19. In the case in which the piezoelectric sensor 33 is provided in thesupport means 35, the resistor 55 for disconnection detection isprovided in the end 53 and the piezoelectric sensor 33 is inserted inthe support means 35, and the piezoelectric sensor 33 and the decidingmeans 19 are then connected and integrated with each other. At the sametime that the support means 35 is to be molded by extrusion molding, thepiezoelectric sensor 33 may be extruded and provided in the supportmeans 35 and the resistor 55 for disconnection detection may be thenprovided in the end 53, and the piezoelectric sensor 33 and the decidingmeans 19 may be thus integrated.

FIG. 5 is a block diagram showing the object detecting device and theopening and closing device according to the embodiment. The decidingmeans 19 comprises a resistor 61 for voltage division which is used fordetecting the disconnection of the pressure sensitive sensor 17, afiltering section 62 for passing only a predetermined frequencycomponent from an output signal sent from the piezoelectric sensor 33, adeciding section 63 for deciding the contact of an object with thepressure sensitive sensor 17 based on an output signal sent from thefiltering section 62, and an abnormality deciding section 64 fordeciding the abnormality of the disconnection of the center electrode 45and the ground electrode 47 in the piezoelectric sensor 33 from avoltage value formed by the resistor 55 for disconnection detection andthe resistor 61 for voltage division. Moreover, a signal input section65 for connecting the center electrode 45 and the ground electrode 47 tothe deciding means 19 and for inputting a signal output from thepiezoelectric sensor 33 to the deciding means 19 and a signal outputsection 66 for outputting a decision signal sent from the decidingsection 63 are provided adjacently in the deciding means 19. A powerline and a ground line to reach the deciding means 19 are also connectedto the signal output section 66. Furthermore, the deciding means 19 hasa bypass section 67 such as a capacitor provided between the signalinput section 65 and the signal output section 66 and serving to bypassa high frequency signal.

The driving means 21 has a hole element 68 for detecting the rotationpulse of the motor 25.

The control means 23 comprises a position detecting section 71 fordetecting the position of the upper end of the windowpane 15 based on anoutput signal sent from the hole element 68, an opening and closingsection contact deciding section 72 for detecting the moving speed ofthe windowpane 15 based on the output signal sent from the hole element68, thereby deciding the contact of an object with the windowpane 15,and a control section 73 for controlling the motor 25 based on theoutput signals of the deciding means 19, the position detecting section71 and the opening and closing section contact deciding section 72.

The position detecting section 71 counts and stores a pulse signaloutput from the hole element 68, thereby detecting the current positionof the upper end of the windowpane 15. A position Y of the upper end ofthe windowpane 15 is represented by a height from the lowermost point ofthe window frame 13 as shown in FIG. 1.

The opening and closing section contact deciding section 72 calculatesthe moving speed of the windowpane 15 from the pulse separation of apulse signal output from the hole element 68 based on the fact that themoving speed of the windowpane 15 is reduced when an object comes incontact with the windowpane 15, and decides that the object comes incontact with the windowpane 15 and outputs a pulse signal of Lo→Hi→Lo ifa change amount |ΔV_(w)| per unit time of the moving speed thuscalculated is greater than a preset value V_(w1). Any pulse signalhaving an Hi level is set to be a decision signal.

Moreover, reporting means 74 for reporting the result of the decision ofthe deciding means 19 by means of a predetermined light provided on afront panel in a vehicle compartment and an opening and closing switch75 for opening and closing the windowpane 15 are connected to thecontrol means 23, and the opening and closing switch 75 includes anauto-up switch and an auto-down switch for opening and closing thewindowpane 15 by a one-touch operation, and a manual-up switch and amanual-down switch for opening and closing the windowpane 15 by a manualoperation. There is provided a power supply 76 comprising a battery of acar which serves to supply a power through the deciding means 19.

The filtering section 62 has such a filtering characteristic as toremove an unnecessary signal caused by the vibration of the body of acar from the output signal of the piezoelectric sensor 33 and to extractonly a peculiar frequency component appearing on the output signal ofthe piezoelectric sensor 33 when the piezoelectric sensor 33 is deformedby pressing due to the contact of an object. In order to determine thefiltering characteristic, it is preferable that the vibrationcharacteristic of the body of the car or the vibration of the bodyduring running should be analyzed and optimized.

In order to remove an external electrical noise, the deciding means 19is wholly covered with a shield member and is thus shieldedelectrically. Moreover, the ground electrode 47 is conducted to theshield member of the deciding means 19 and the pressure sensitive sensor17 is also shielded electrically. A countermeasure for a high electricfield may be taken by adding a feed-through capacitor or an EMI filterto the input/output section of the circuit.

Next, description will be given to a basic operation for detecting thecontact of an object with the pressure sensitive sensor 17 by the objectdetecting device.

FIG. 6 shows the state of the pressure sensitive sensor 17 in the casein which an object 77 enters and is pinched between a window frame and awindowpane. When the object 77 comes in contact with the photosensitivesensor 17, the pressing of the object 77 is applied to the support means35 and the piezoelectric sensor 33. The support means 35 has a moreflexibility than the piezoelectric sensor 33. Therefore, the supportmeans 35 is compressed by the pressing around a point in which theobject 77 comes in contact as shown so that the side wall section 43 isdeformed and the hollow section 41 is crushed simultaneously.Consequently, the piezoelectric sensor 33 is also bent and deformedaround a point in which the object 77 comes in contact with the supportmeans 35. Moreover, also when the window frame including the pressuresensitive sensor 17 is gripped by hand, the same deformation isgenerated in the pressure sensitive sensor 17.

When the piezoelectric sensor 33 is thus deformed, an output signalcorresponding to the deformation is output from the piezoelectric sensor33 by a piezoelectric effect. The signal output from the piezoelectricsensor 33 is filtered by the filtering section 62. In some cases, anoutput signal generated by an unnecessary vibration component caused bythe vibration of the body of a car appears in the output signal of thepiezoelectric sensor 33. The filtering section 62 removes theunnecessary signal.

A procedure for the operations of the deciding section 63 and thecontrol section 73 will be described with reference to FIGS. 7A to 7C.FIGS. 7A to 7C are characteristic charts showing an output signal V sentfrom the filtering section 62, a decision output J of the deciding means19, and a voltage V_(m) to be applied to the motor 25. In FIGS. 7A to7C, an axis of ordinate indicates V, J and V_(m) from the top and anaxis of abscissa indicates a time t. When the auto-up switch of theopening and closing switch 75 is turned ON at a time t₁, the controlsection 73 applies a voltage of +V_(d) to the motor 25 to cause thewindowpane 15 to carry out a closing operation. The deciding means 19carries out a deciding operation during the closing operation of thewindowpane 15. When the object 77 is pinched as shown in FIG. 6, asignal corresponding to the acceleration of the deformation of thepiezoelectric sensor 33 is output from the piezoelectric sensor 33 bythe piezoelectric effect and a greater signal component than a referencepotential V₀ shown in FIG. 7A appears from the filtering section 62. Inthis case, with such a structure that the piezoelectric sensor 33 issimply provided in the window frame 13, the piezoelectric sensor 33 isslightly deformed during pinching. In the embodiment, the support means35 has a flexibility as shown in FIG. 2 and is easily compressed duringthe pinching so that the amount of the deformation of the piezoelectricsensor 33 is increased.

Since the hollow section 41 is also crushed during the pinching, theamount of the deformation of the piezoelectric sensor 33 is furtherincreased. Thus, the large amount of the deformation can be obtained forthe piezoelectric sensor 33 and an acceleration to be a secondarydifferential value of the amount of the deformation is also increased.As a result, the output signal of the piezoelectric sensor 33 is alsoincreased. The deciding section 63 decides that a contact with theobject 77 is caused if an amplitude of |V−V₀| of V from V₀ is greaterthan D₀ (a first change amount) and outputs a pulse signal of Lo→Hi (adecision signal)→Lo as a decision output at a time t₂ as shown in FIG.7B.

The control section 73 stops the application of a voltage of +V_(d) tothe motor 25 as shown in FIG. 7C in response to the decision signal ifany and applies a voltage of −V_(d) for a constant time till a time t₃to bring down the windowpane 15 in a constant amount, thereby releasingpinching or preventing the generation of the pinching. In the case inwhich a pressure to be applied to the pressure sensitive sensor 17 is tobe released, a signal corresponding to an acceleration restoring thedeformation (a smaller signal component than the reference potential V₀in FIG. 7A) is output from the piezoelectric sensor 33.

In the deformation of the pressure sensitive sensor 17, the comparisonof V with V₀ is changed depending on the direction of bending orpolarization of the piezoelectric sensor 33, the allotment of anelectrode (a decision of one of them to be a reference potential) andthe direction of support of the piezoelectric sensor 33. Since thedeciding section 63 decides the pinching based on the absolute value ofthe amplitude of V from V₀, the pinching can be decided irrespective ofthe comparison of V with V₀.

In addition to the basic deciding method, it is possible to prevent thegeneration of the pinching by deciding the presence of a contact with anobject in the following manner.

FIGS. 8A and 8B are characteristic charts showing an output signal Vsent from the filtering section 62 and a decision output J of thedeciding means 19. In FIGS. 8A and 8B, an axis of ordinate indicates Vand J from the top and an axis of abscissa indicates a time t.

As shown in FIG. 8A, when the pressure sensitive sensor 17 is displacedby gripping the window frame 13 at a time t₄, a signal is output fromthe piezoelectric sensor 33 by the piezoelectric effect. As a result, agreater signal component than the reference potential V₀ is generatedfrom the filtering section 62.

In the case in which the output signal V is equal to or greater thanpreset V₁, that is, the amplitude of |V−V₀| of the output signal V fromV₀ is greater than V₁ (a first change amount), the deciding section 63decides that a contact with the object is caused, and outputs and holdsa pulse signal Lo→Hi (decision signal) as a decision output at the timet₄ as shown in FIG. 8B. Next, when the window frame 13 is released tocancel the displacement of the pressure sensitive sensor 17, a signal isoutput from the piezoelectric sensor 33 by the same piezoelectric effectand a smaller signal component than the reference potential V₀ appearsfrom the filtering section 62. At this time, in the case in which theoutput signal V is equal to or smaller than preset V₂, that is, theamplitude of |V−V₀| of the output signal V from V₀ is greater than V₂ (asecond change amount), the deciding section 63 decides that the objectis separated and sets, to Hi→Lo, a pulse signal having an Hi level to bea decision signal at a time t₅. In other words, the pulse signal ismaintained to be Hi and the output of the decision signal is held whilethe contact of the object is detected and the separation is thendetected.

From the time t₄ that the decision signal is output and the contact ofthe object is then detected to the time t₅ that the separation of theobject is detected, the control section 39 controls to lock theoperation of the windowpane 15 even if the opening and closing switch 75is operated to bring up or down the windowpane 15. Consequently, anobstacle is detected so that the generation of pinching can beprevented, resulting in an enhancement in safety.

The output signal V is changed depending on a polarity when thepiezoelectric sensor 33 is to be polarized. In that case, the positiveand negative signs of a signal shown in the drawing are reversed.Therefore, it is preferable that the positive and negative signs of theset values of V₁ and V₂ should be reversed.

Moreover, it is also possible to have such a structure that the controlmeans 23 side to be connected can have the function of the decidingmeans 19, thereby separating the deciding means 19 from the pressuresensitive sensor 17, resulting in an enhancement in the management ofthe installation of the pressure sensitive sensor 17 itself.

Furthermore, in the case in which the contact and separation of theobject is to be detected based on a signal output from the piezoelectricsensor 33, the structure of the conventional support means 35 shown inFIG. 15 may be employed.

Next, the function of the support means 35 will be described.

In addition to the basic structure, the pressure sensitive sensor 17according to the invention has such a structure that the support means35 has at least the first deformation section 37 and the seconddeformation section 39 so that the deformation can also be detected attime of the application of a static load and a pressure can be detectedmore reliably.

FIGS. 9A to 9C show states in which a pressure is detected in acompression state, FIG. 9A being an explanatory view showing theapplication of a static load, FIG. 9B being an explanatory view showinga state in which a pressure is further applied, and FIG. 9C being anexplanatory view showing a state in which a pressure is detected toreturn a windowpane.

As shown in FIG. 9A, a state in which the window frame 13 is gripped istaken as an example in which the pressure sensitive sensor 17 hasalready been set in a compression state. Conventionally, even if a loadin a compression direction is more applied, a displacement generated inthe pressure sensitive sensor 17 is very small. In order to obtain adetection signal from the piezoelectric sensor 33 on a sufficient outputlevel, accordingly, it is necessary to use the piezoelectric sensor 33having a high sensitivity. For this reason, there is a problem in that acost is increased. On the other hand, in the pressure sensitive sensor17 according to the invention, the first deformation section 37 isconnected to the window frame 13 through the second deformation section39. Even if the first deformation section 37 is completely crushed in aninitial state, therefore, the second deformation section 39 is mainlydeformed when a pressure is further applied by the pressing of thewindowpane 15 to bring a state shown in FIG. 9B. Also in the compressionstate in which the first deformation section 37 is crushed,consequently, the piezoelectric sensor 33 is deformed so that adetection signal can reliably be obtained at a sufficient output level.When the windowpane 15 is stopped and is started to be brought down uponreceipt of the detection signal from the piezoelectric sensor 33 asdescribed above, the original state of FIG. 9A is set again as shown inFIG. 9C.

FIG. 10 shows a graph representing the deformation characteristics ofthe first deformation section 37 and the second deformation section 39.In other words, the pressure sensitive sensor 17 is accommodated in thesupport means 35 having a plurality of (two in the embodiment)deformation characteristics. In the initial deformation of the pressuresensitive sensor 17 in which the whole window frame 13 is gripped, thefirst deformation section 37 having a small macro elastic modulus (E1)is mainly deformed correspondingly. After a compression state having aconstant level is brought, the second deformation section 39 having agreat macro elastic modulus (E2) is deformed mainly. By constituting thesupport means 35 to have a deformation behavior in a plurality ofstages, a detection signal having a sufficient level for detection canbe obtained from the piezoelectric sensor 33 even if the pressuresensitive sensor 17 is put under a stress.

In addition to the state in which the static load is applied and thefirst deformation section 37 is thus crushed, moreover, the seconddeformation section 39 is deformed also when a dynamic load such as avibration is applied. Consequently, the applied pressure can be detectedreliably at a low cost.

Next, a variant of the support means having the deformationcharacteristics will be sequentially described below. The same membersas those shown in FIG. 2 have the same reference numerals anddescription thereof will be omitted.

FIG. 11 is a sectional view showing a first variant in which the seconddeformation section is constituted separately from the weather strip.

A first deformation section 37 according to the variant is formedseparately from a weather strip 81 and is bonded to a second deformationsection 83 fixed to a window frame 13. The second deformation section 83is formed by a material having a greater elastic modulus E2 than a macroelastic modulus E1 of the first deformation section 37. For example, thesecond deformation section 83 may be formed of harder rubber than thefirst deformation section 37.

Thus, the second deformation section 83 is formed separately from theweather strip 81. Consequently, the degree of freedom of the design ofthe weather strip 81 can be enhanced, and furthermore, the bonding tothe first deformation section 37 is eliminated so that the degree offreedom of material selection can also be enhanced.

Next, a second variant of the support means will be described.

FIG. 12 is a sectional view showing a structure according to the secondvariant in which a second deformation section is integrated with a firstdeformation section.

In the variant, a first deformation section 37 and a second deformationsection 85 are formed integrally, and the second deformation section 85has a gap 87 which is smaller than a hollow section 41 of the firstdeformation section 37. The gap 87 may comprise a plurality of bubblesshown in the drawing and a plurality of very small hollow sections maybe formed. By the gap 87, the first deformation section 37 is crushedand the second deformation section 85 is then deformed. Thus, a pressurecan be detected stably under a compressive stress. According to such astructure, moreover, the first deformation section and the seconddeformation section can be processed by integral molding. Consequently,a manufacturing process and an assembling process can be simplified.

Next, a third variant of the support means will be described.

FIG. 13 is a sectional view showing a structure according to the thirdvariant in which a second deformation section and a first deformationsection are integrated.

In the variant, a first deformation section 37 and a second deformationsection 89 are formed integrally and the second deformation section 89has a great thickness such that a distance L from a window frame 13 onthe fixing side of support means 35 has a predetermined value or more.By the distance L, the first deformation section 37 is crushed and thesecond deformation section 89 is then deformed by its own elasticity.Consequently, a pressure can be detected stably under a compressivestress. Conventionally, the amount of the deformation of the seconddeformation section 89 is very small because the distance L is short.Consequently, a sufficient deformation margin cannot be taken. Byincreasing the distance L, however, the piezoelectric sensor 33 caneasily be deformed and a pressure can be detected stably. Moreover, thefirst deformation section 37 and the second deformation section 89 canreadily be molded integrally.

In addition to the structure according to each of the variants, thefollowing structure can also be employed. More specifically, as shown inFIG. 14A, in the case in which an object 77 presses the pressuresensitive sensor 17 during the closing operation of a windowpane, thepressure sensitive sensor 17 does not detect that the windowpane 15 ispressed against the object 77 when the window frame 13 has a highrigidity. By setting the rigidity of the window frame 13 to be lower bya predetermined amount, however, the window frame 13 is elasticallydeformed and flexed when the windowpane 15 is pressed against the object77 as shown in FIG. 14B. By the flexure, a detection signal having asufficient output level can be obtained from the piezoelectric sensor.More specifically, the window frame 13 has the function of the seconddeformation section.

According to the pressure sensitive sensor, the object detecting deviceand the opening and closing device described above, the processing of asignal sent from the piezoelectric sensor is varied or the shape of thesupport means is changed. Consequently, a detection capability can beenhanced at a low cost. In other words, also in the case in whichexternal force is suddenly applied to the pressure sensitive sensor, atime taken from the start of a contact to the end thereof is recognizedbased on a signal output from the piezoelectric sensor and a drivingoperation for this period can be locked. Also in the case in whichexternal force is applied under a static pressure in which a pressure ispreloaded to the pressure sensitive sensor, moreover, the seconddeformation section of the support member is deformed so that a signalhaving a sufficient output level can be obtained from the piezoelectricsensor and reliable detection can be carried out. By these effects, anobstacle can be detected reliably to prevent pinching so that stabilitycan be enhanced still more.

Moreover, the invention is not restricted to a pressure sensitive sensorto be provided in the window frame of a car but can also be applied tothe slide door of the side surface of a body in a car, an electricallyoperated sunroof provided on the ceiling of the body, an electricallyoperated hatch door in the rear part of the body or an electricallyoperated trunk, for example, and the same advantages as those describedabove can be obtained. Furthermore, the invention is not restricted tothe car but can also be applied to an automatic door of a train or abuilding.

According to the invention, an object can be detected stably with highprecision at a low cost in any situation by using the piezoelectricsensor for detecting an acceleration component, can enhance the effectof detecting an obstacle and preventing pinching, and can improve safetystill more.

Second Embodiment

As shown in FIG. 2B, the pressure sensitive sensor 17 according to thesecond embodiment comprises a flexible piezoelectric element member 33to be voltage sensing means, and elastic support means 35 having ahollow section 42 for inserting and supporting the piezoelectric elementmember 33.

The elastic support means 35 is formed by an elastic member such assynthetic rubber or a foamed resin member, and is attached along theedge of the window frame 13 in order to fulfill the function as apacking by adhesion to the windowpane 15 and the function for bufferingthe contact section of the windowpane 15, and is provided with thehollow section 42 for inserting the piezoelectric element member 33 inthe vicinity of a lower most section thereof.

Bemaining configurations are equivalent to that of the first embodiment.

In the pinching detecting device 100 and the opening and closing device150 according to the second embodiment, the elastic support means 35 isstuck, over an almost whole length, onto an inclined surface 161 of thewindow frame 13 opposed to the upper edge of the windowpane 15 and theother side connected thereto through a corner section, that is, ahorizontal upper side 163 crossing the upper end of the inclined side161 almost horizontally respectively as shown in FIG. 16.

In the corner section 165 of the window frame 13 at which the inclinedside 161 crosses the horizontal upper side 163, the butt ends of theelastic support means 35 a stuck to the inclined side 161 and theelastic support means 35 b stuck to the horizontal upper side 163 arecut obliquely at a predetermined angle and are then bonded such that thehollow section 42 for inserting the piezoelectric element member of eachof the elastic support means 35 a and 35 b smoothly communicates at thebutt ends of the respective elastic support means 35 a and 35 b as shownin FIG. 17 to be an enlarged view illustrating a B portion in FIG. 16.

The pressure sensitive sensor 17 according to the embodiment has such anattachment structure that one long piezoelectric element member 33 isinserted in the communicating hollow section 42 of the respectiveelastic support means 35 a and 35 b and is connected to the decidingmeans 19.

In the attachment structure of the pressure sensitive sensor 17 havingsuch a structure, the piezoelectric element member 33 is continuous. Forthis reason, an insensitive part is not present in the corner section165 and a whole region in which the pressure of the window frame 13 isto be detected can be set to be a pressure detection region without aclearance. Moreover, the pressure sensitive sensor 17 is a piezoelectricelement for outputting an electric signal corresponding to a deformationacceleration in the elastic deformation. Also in the case in which thepressure sensitive sensor 17 is provided in the corner section 165 ofthe window frame 13 in a bending state, therefore, the bent section ofthe piezoelectric element member 33 for the provision is deformed and asignal indicative of pinching is not output until elastic deformation isnewly received. Accordingly, the pressure sensitive sensor 17 can beprovided without a hindrance such as erroneous detection across thecorner section 165 of the window frame.

Moreover, the pressure sensitive sensor 17 is a piezoelectric elementfor outputting an electric signal corresponding to a deformationacceleration in elastic deformation. As compared with a conventionalpressure sensitive sensor 17 for outputting a signal by a contact ofcontact wires during the elastic deformation in a constant amount,therefore, a signal indicative of the generation of slight elasticdeformation can also be output quickly.

For example, as shown in FIG. 18A, in the case in which an object 167 ispinched within a range of the inclined side 161 of the window frame 13as shown in FIG. 18A, a component of force FN in a direction orthogonalto an inclined side which generates elastic deformation on thepiezoelectric element member 33 of the inclined side 161 is much smallerthan energizing force F in the closing direction of the windowpane 15 asshown in FIG. 18B so that only small elastic deformation is generatedwhen the object 167 is pinched. However, the piezoelectric elementmember 33 outputs a signal corresponding to the deformation accelerationof slight elastic deformation. Therefore, the pinching can be detectedreliably and rapidly on the deciding means 19 side.

More specifically, the pressure sensitive sensor 17 according to theembodiment can detect the generation of the pinching reliably andrapidly also in the case in which it is provided in the inclined sectionand the corner section 165 in the window frame 13. Therefore, theesingle long pressure sensitive sensor 17 is continuously provided over awhole provision region on the window frame including the inclinedsection thereof and the corner section 165. Thus, only one pressuresensitive sensor 17 to be provided is enough. As a result, the number ofthe pressure sensitive sensors 17 to be used for one opening section isreduced to one and the processing of a signal line led from the pressuresensitive sensor 17 can easily be carried out as described in theembodiment.

In the embodiment, moreover, the pressure sensitive sensor 17 to beprovided in one opening is set to be the single long piezoelectricelement member 33. For example, also in the case in which the object ispinched in the inclined side 161 as described above and elasticdeformation toward the contact section of the object is small at thattime, therefore, one continuous piezoelectric element member 33 ispulled in the acting position of pressing force F_(N) generated by thecontact of the object as shown in FIG. 19 and a section other than thecontact section with the object is also deformed up to the circumferenceof the contact section as shown in a solid line from a position shown ina broken line of FIG. 19 and a signal corresponding to a deformationacceleration is output by the surrounding deformation. Therefore, agreat detection signal can be output as a whole of the piezoelectricelement member 33 so that the contact of the object can be detectedreliably and rapidly.

In the embodiment, moreover, the piezoelectric element member 33 isformed by a compound piezoelectric member mixing chlorinatedpolyethylene and piezoelectric ceramics powder. With such a structure,the piezoelectric element member 33 can maintain a flexibility withwhich a section is greatly deformed by the action of slight externalforce. Also in the case in which force acting when pinching is generatedbecomes a smaller component of force than force for closing thewindowpane as in the inclined section of the window frame of a frontdoor in a vehicle, therefore, the piezoelectric element member 33 can begreatly deformed elastically when the pinching is generated, therebydetecting the pinching reliably and rapidly.

In the opening and closing device 150 having the pressure sensitivesensor 17 attached thereto as described above, moreover, in the case inwhich an object is pinched between the windowpane 15 and the edge of thewindow frame 13 during an operation for closing the windowpane 15 to bean opening and closing member, the pressure sensitive sensor 17 havingthe attachment structure detects the generation of the pinching reliablyand rapidly and an operation for closing the opening and closing memberis stopped or an operation for opening the opening and closing member isstarted immediately based on the result of the detection. Consequently,it is possible to reliably prevent an accident from being caused by thedetection delay of the pinching or detection failures.

Accordingly, the opening and closing device 150 is very useful forpreventing a hand or a finger from being damaged by pinching in a powerwindow device for opening and closing the windowpane of a vehicle bymeans of an electric motor.

Next, another embodiment according to the invention will be described.

FIGS. 20A to 20B show examples of the structure of a door section on therear seat side of a car. FIG. 20A shows such a structure that apartition frame 82 is provided in addition to window frames 81 a, 81 band 81 c and a fixed window 83 is provided between the partition frame82 and the window frames 81 a, 81 b and 81 c, and a windowpane 84 isbrought up and down without a clearance between the window frame 81 aand a guide 85 connected thereto and the partition frame 82 and a guide86 connected thereto. In this case, it is preferable that the pressuresensitive sensor 17 should be provided in only the window frame 81 b inorder to prevent an object from being pinched.

In recent years, however, there have been so many structures in which apartition frame is not provided as shown in FIG. 20B in respect of adesign. With such a structure, when the windowpane 84 is brought up anddown, a clearance is generated between the windowpane 84 and the windowframe 81 c. For this reason, it is necessary to prevent an object frombeing pinched in the clearance. However, when a conventional pressuresensitive sensor of a contact type is provided in the inclined windowframe 81 c, erroneous detection is caused by the connection of a contactor force acting on the pressure sensitive sensor 17 becomes a componentof force as described above. As a result, there is a drawback that thepinching of the object cannot be detected quickly.

By providing the pressure sensitive sensor according to the invention inthe window frame 81 c, therefore, a signal indicative of generation ofslight elastic deformation can be output quickly because the pressuresensitive sensor is constituted by the piezoelectric element. Thus, thepinching of the object between the window frame 81 c and the windowpane84 can be detected reliably and rapidly.

Moreover, since the piezoelectric element member 33 of the pressuresensitive sensor 17 according to the invention can be bent, it may beprovided from the window frame 81 c toward the window frame 81 b. Inthat case, it is possible to detect pinching in both regions of thewindow frames 81 b and 81 c by means of one pressure sensitive sensor.

It is preferable that the elastic support means 35 according to each ofthe embodiments described above should be subjected to a high frictionprocessing for causing an object to slide over a surface with difficultyin the direction of provision of the pressure sensitive sensor during acontact with the object in a region provided in at least the inclinedsection of the window frame. Consequently, the object can be preventedfrom sliding over the surface of the elastic support means 35 followingthe operation of the windowpane.

The high friction processing includes the following specific examples.More specifically, the processing can be carried out by a method offorming very small concavo-convex shapes simultaneously with theextrusion molding of the elastic support means 35, a method of formingthe elastic support means 35 by the extrusion molding and then pushing athermal mold to finish a crimped surface, and a method of formingconcavo-convex sections on the surface of the elastic support means 35after the molding by means of a grinder or a sandpaper and roughing thesame surface. Moreover, the surface of the elastic support means 35 maybe subjected to coating. For example, a coating material such as anurethane based or epoxy based material having a high coefficient ofstatic friction or a viscous material having a low viscosity is appliedso that a coating layer having a high friction can be formed.Furthermore, the elastic support means 35 may be formed of a materialwhich is rarely slippery.

In the case in which a rubber material is generally applied toindustrial products such as a car, moreover, the provision of a lowfrictional coating layer on a surface is extensively carried out inorder to reduce a friction and to enhance beauty and durability. It ispreferable that the elastic support means 35 should have a highfriction. Therefore, it is preferable that the surface of the wholeelastic support means 35 or a part thereof should be a surface fromwhich a material surface having no low frictional coating layer isexposed. More specifically, at least a section for detecting an objectis not subjected to low friction coating but is brought into an almostexact surface state after a material processing such as extrusionmolding. Then, the section for detecting an object may be masked and theother sections may be subjected to the low friction coating ifnecessary. Consequently, it is possible to form a high frictionalsurface on the elastic support means 35 by simply changing amanufacturing process.

Preferably, the high friction processing is not restricted to theelastic support member 35 but is carried out for the weather strip 14(see FIG. 2B) in the same manner.

Although the above-described second embodiment, the elastic supportmember 35 as shown in FIG. 2B is used. It should be understand that itcan be used the elastic support member 35 having first deformableportion 37 and second deformable portion 39 as shown in FIG. 2A of thefirst embodiment.

The application object of the pressure sensitive sensor attachmentstructure and the opening and closing device according to the inventionis not restricted to the power window device of a front or rear seat ina car described in the embodiment. As shown in FIG. 21, they can also beapplied to an electrically operated back door window 175 forelectrically opening and closing a windowpane 173 with respect to awindow frame 171 of a back door 170 of a car.

Moreover, the invention is not restricted to a pressure sensitive sensorto be provided in the window frame of a car but can also be applied tothe slide door of the side surface of a body in a car, an electricallyoperated sunroof provided on the ceiling of the body, an electricallyoperated hatch door in the rear part of the body or an electricallyoperated trunk, for example, and the same advantages as those describedabove can be produced. Furthermore, the invention is not restricted tothe car but can also be applied to an automatic door of a train or abuilding.

According to the pressure sensitive sensor attachment structure of theinvention, a pressure, sensitive sensor is a piezoelectric element foroutputting an electric signal corresponding to a deformationacceleration in elastic deformation. Even if the pressure sensitivesensor is provided in a corner section in a bending state, therefore, asignal indicative of pinching is not output until a bent section for theprovision is newly deformed by pinching an object. Thus, the pressuresensitive sensor can be provided across the corner section such as awindow frame. Moreover, the pressure sensitive sensor is thepiezoelectric element. As compared with a conventional pressuresensitive sensor for outputting a signal by a contact of contact wiresduring elastic deformation in a constant amount, therefore, a signalindicative of the generation of slight elastic deformation can be outputquickly. For example, also in the case in which the pressure sensitivesensor is provided on the inclined side of the window frame, thegeneration of pinching can be detected reliably and rapidly.

Accordingly, a single long pressure sensitive sensor can be continuouslyprovided over the whole provision region on the window frame includingthe inclined section and the corner section in the window frame and onlyone pressure sensitive sensor to be provided is enough. Consequently,the number of the pressure sensitive sensors to be used is reduced toone for one opening section and the processing of a lead wire led fromthe pressure sensitive sensor can easily be carried out.

In the opening and closing device according to the invention, moreover,in the case in which an object is pinched between an opening and closingmember and the edge of an opening section during the closing operationof the opening and closing member, the pressure sensitive sensorattached with the pressure sensitive sensor attachment structure detectsthe generation of the pinching reliably and quickly. Based on the resultof the detection, the closing operation of the opening and closingmember is stopped or the opening operation of the opening and closingmember is started immediately. Therefore, it is possible to reliablyprevent an accident from being caused by the detection delay of thepinching or detection failures. In a power window device for opening andclosing the windowpane of a vehicle by an electric motor, accordingly,the opening and closing device is very useful for preventing a hand or afinger from being damaged by pinching.

1. A pressure sensitive sensor attachment structure, comprising: apressure sensitive sensor for outputting a signal corresponding to anacceleration due to deformation of the sensor, and an elastic supportmeans, wherein the attachment structure is provided in at least one ofan opening section having an inclined side and another side connectedthereto through a corner section and an opening and closing member foropening and closing the opening section and serving to detect pinchingof an object between the opening section and the opening and closingmember, wherein the pressure sensitive sensor has a flexibility and islong, and is inserted in the elastic support means to be supported onthe opening section or the opening and closing member, and is providedon at least the inclined side of the opening section.
 2. A pressuresensitive sensor attachment structure, comprising: a pressure sensitivesensor for outputting a signal corresponding to an acceleration due todeformation of the sensor, and an elastic support means, wherein theattachment structure is provided in at least one of an opening sectionhaving an inclined side and another side connected thereto through acorner section and an opening and closing member for opening and closingthe opening section and serving to detect pinching of an object betweenthe opening section and the opening and closing member, wherein thepressure sensitive sensor has a flexibility and is formed like a longshaft, and is inserted in the elastic support means to be supported onthe opening section or the opening and closing member, and the singlecontinuous pressure sensitive sensor is inserted in the elastic supportmeans in a region including the inclined side and another side.
 3. Thepressure sensitive sensor attachment structure according to claim 1 or2, wherein the pressure sensitive sensor serves includes a piezoelectricdevice.
 4. The pressure sensitive sensor attachment structure accordingto any of claims 1 to 2, wherein a piezoelectric element material of thepressure sensitive sensor is formed by a compound piezoelectric membermixing chlorinated polyethylene and piezoelectric ceramics powder. 5.The pressure sensitive sensor attachment structure according to claim 1or 2, wherein a surface of the elastic support means is subjected to ahigh friction processing.
 6. The pressure sensitive sensor attachmentstructure according to claim 1 or 2, wherein a surface of the wholeelastic support means or a part thereof is a surface from which amaterial surface having no coating layer is exposed.
 7. An opening andclosing device comprising: the pressure sensitive sensor attached withthe pressure sensitive sensor attachment structure according to claims 1or 2; deciding means for deciding presence of a contact of an objectwith the pressure sensitive sensor based on the signal output from thepressure sensitive sensor; opening and closing means for operating theopening and closing member for opening and closing the opening section;and control means for controlling the opening and closing means in orderto stop the operation of the opening and closing member or to start anopening operation of the opening and closing member when the decidingmeans decides that the contact with the object is caused in response tothe signal sent from the pressure sensitive sensor.